The present invention relates generally to devices that produce a biogas, such as methane, and particularly to devices that use anaerobic digestion processes to convert biological waste materials into a biogas.
The treatment and management of organic waste materials poses many problems, especially for the environment. For example, anaerobic lagoons are the traditional means by which some farmers dispose of organic waste materials produced by hogs, cows, and other animals. Anaerobic lagoons, which are sometimes referred to as “hog lagoons,” are open-air pits formed in the ground that can hold millions of gallons of liquefied organic waste material. Anaerobic organisms such as bacteria are naturally present in the animal waste, and over time, decompose the waste material in the lagoon.
Managing the waste of the hogs and other animals, however, presents a significant challenge. For example, the stench produced by hog lagoons is highly offensive. Additionally, hog lagoons are prone to rupture after a heavy rain. Particularly when a lagoon ruptures, the raw waste material within the lagoon can spill into fields, rivers, creeks, and other waterways, and cause serious environmental damage.